The present invention relates to a seal assembly for sealing a clearance space or gap between first and second displaceable cylindrical surfaces, and more particularly to a seal assembly which includes an inclined “L” or foot-shaped element in contact with one of the cylindrical surfaces.
Seal assemblies designed for leakage control of fluid in pressurized hydraulic systems are generally known in the art. Such seals may be found, for example, in aerospace applications, including flight-controls, landing gears and hydraulic actuators. The seals used in such applications may have a variety of different geometries, while all performing generally the same function. Seals of different shapes and/or materials are better suited for different types (e.g., operating conditions) of applications. One problem with the seals for high-pressure hydraulic applications generally known in the art is that the sealing or cap element is often not energized in a manner such that the sealing element applies uniform pressure to the cylindrical surface which it contacts. Additionally, some of the hydraulic seals known in the art are not capable of withstanding the extreme high pressures and/or temperatures associated with highly-pressurized hydraulic systems. Accordingly, many of the prior art hydraulic seals are prone to leakage due to excessive wear and/or non-uniform load distribution on the cap element.
Accordingly, it is desirable to have a seal assembly for sealing a clearing space between first and second displaceable surfaces which is capable of preventing leakage in a high-pressure, high-temperature hydraulic system, by providing a uniform load distribution on the cap element, thereby resulting in longer seal life and better sealability. It should be noted that it is desirable to use simple hardware particularly in aerospace applications, since complexity of construction adds undesirable weight and cost. Therefore, closed-wall grooves for containing seals are required. This demands seal designs that are sufficiently flexible in construction to allow enough deformation for installation into closed-wall grooves while still providing adequate resistance to pressure extrusion, sealing efficiency and wear resistance. This is particularly applicable for rod-type seals and also for retro-fitting seals into existing gland configurations.